1. Field
One or more exemplary embodiments of the present invention relate to a varifocal lens having a focal length that may be electrically controlled, and an imaging apparatus including the varifocal lens.
2. Description of the Related Art
A varifocal lens may continually vary its focal length. Generally, a varifocal lens includes a plurality of lens elements, and may vary its focal length by changing relative positions of the lens elements. Such a varifocal lens having many lens elements is relatively large and heavy, and the varifocal lens needs driving devices for controlling the respective lens elements.
Recently, the need for a zoom system has arisen in small-sized cameras integrated with mobile devices such as cellular phones, personal digital assistants (PDAs), and notebook computers. However, it is difficult to use a varifocal lens including many lens elements in such a small-sized camera. It may be convenient to use a single lens element having a variable focal length in a zoom system of a small-sized camera. Thus, research has been conducted into a varifocal lens using a material such as a liquid crystal whose refractive index may be changed by electrically controlling the liquid crystal.